The invention relates to a support material for tissue culture and cell culture (tissue engineering) for the production of implant materials, in particular bone, cartilage or skin replacements or extra-corporal organ replacements or for other applications in medicine or biotechnology. The invention further relates to an implant produced with the scaffold.
It is already known to cultivate cells on support material (scaffold) and use the thereby produced tissue culture as a tissue replacement. For example, gels, fiber materials, porous ceramics or other two- or three-dimensional structures are used as scaffolds. The treatment of different tissues, for example, cartilage, that are defective through injury, wear or sickness by means of grown tissue cultures is already known. For this purpose, endogenous cells are introduced, for example, into three-dimensional scaffolds, proliferated in vitro, and the material so produced is implanted in the body. The support materials used in biocompatible implants have substantial influence on the colonization, cell growth and future function of the implant.
Fiber materials offer large surfaces for contact with cells and form open-pored structures, which are necessary for the supply of the cells with nutrient solution. Today, non-woven materials are often used, which however show disadvantageous inhomogenities in their structure. Thus, cells will grow only very slowly through larger free spaces between the fibers. In areas where the fibers lie very tightly together, the cell density is in contrast very low. The organisation of the fiber arrangement in non-woven structures is only possible to a limited extent due to the high variance of the fiber orientation. Even though textile materials made out of threads are very well structured (see above), the distances between the fibers are extremely variable. Within the threads, which usually consist of 20 to 200 fibers each, the fibers lie extremely close together, and very large distances often exist between the threads.
Scaffolds made from textile materials, particularly from non-woven materials, fiber textiles or knitted textiles, show a very low compressive stability due to the predominantly horizontal arrangement of the fibers. For example, a melt-blown process for the production of three-dimensional air-intermingled non-woven substances is known from DE 199 59 088. The non-woven substances have pore sizes between 20 μm and 500 μm and a porosity of <95%.
DE 197 21 661 A1 discloses rods arranged in a three-dimensional lattice for the production of bone and cartilage replacement structures for immediate use in vivo. These rods consist of biopolymeric, thermoplastic materials and are built up layer by layer to a three-dimensional lattice by means of selective laser sintering from a layer in powder form or a three-dimensional printing (3-DP) process, which is similar to the functional principle of an ink-jet printer.